5 Weeks Cervix Hard And Low

Why you should have at least intermediate level knowledge of science, if you are out medical press releases ...

... or: Gene, Gene, Gene and the evil junk DNA!

This is again a good example of why I usually refrain to read press releases. A research group has shown in a recent paper in Nature that can help microRNA (miR-21) for disease of heart muscle disease. The interesting thing is that they connect showed between one of the many gene silencing mechanisms and a human disease. Mind you, this compound has long been known, as the authors themselves write already in the abstract of the article. So far everything is still OK.

But what makes the press office of participating in the work of Rudolf Virchow Center of it?

"genetic garbage" triggers heart muscle weakness from

Würzburg, 30.11.2008. Tiny fragments of the genome - so-called "micro-RNAs, which until recently were regarded as unimportant, could now revolutionize the prevention, diagnosis and treatment of heart failure. Würzburg researchers found such a first time in the heart, they blocked and thus could not only protect endangered mice before the onset of the disease, but also to heal diseased heart muscle disease mice. The results describe the scientists of the University of Würzburg in the prestigious science journal Nature.

The decoding of the human genome took a surprising message with it: Only about 1.5 percent of the total genetic information is needed for the production of our proteins, where the genes are a kind of copy that messenger RNA transcribed into proteins. The rest of the genes was long regarded as meaningless "genetic garbage" because their RNA without significant Function was. In 2006, however, for the discovery that RNAs, from which no proteins, important functions in the body of the Nobel Prize for Medicine awarded have [sic]. These RNA fragments regulate the formation of the proteins directly binding to the messenger RNA. Is something wrong, the body produces for example, too much or too little protein, the unit cell of the body out of balance - caused diseases.

The press release goes on, but deals with this seemingly very interesting topic but no more. Maybe because it was known in the press office nothing more pro-depth than this superficial blah?
Let's go the whole thing from the front to the rear. The title is already great, "genetic garbage" in the same scare quotes , and somehow it sounds as if at last the ultimate cause of heart failure was found. On the genetic garbage, so the junk DNA, I would be talking in more detail, now only time will unravel the message.
First movement - microRNAs (again scare quotes) are by no means "fragments of the genome," and they were not until recently as unimportant. Rather, microRNAs as well as all other genes (including those that code for proteins) is first transcribed times, ie, a copy of the gene in the form of RNA produced. When genes are called proteinogenic this RNA, mRNA (messenger RNA). When genes for microRNAs, well, microRNA halt. Would it really fragments of DNA, it would be one part microDNA, and the other, the cell would be dead (broken chromosomes and so). A quick search on PubMed also show that at least written since 2001 about microRNAs - not "recently" so. Let us not only this subfamily of regulatory RNAs, but the whole process of gene silencing , then the statement is even more ridiculous. About post-transcriptional gene-silencing is then written since 1955 (with almost 19 000 articles published to date), and on the information side e for the (in the press release so explicitly mentioned) Nobel Prize (Fire and Mello, 2006) is taken directly relating to work in plants and fungi in 1990.
In the second paragraph then goes merrily Keep it up. Since the text is contrary to first violent. On the one hand, to be only 1.5% of the genome genes ("for the production of our proteins required"), on the other hand, the rest of the genome is probably full of genes ("The rest of the genes")!

This sentence is full of errors anyway:

The rest of the genes was meaningless as long as "genetic garbage" because the RNA was no significant function.

So, no definition of what a gene. Actually, even an admission since the 7th who paid attention in class not to biology class. Taken literally, the author apparently assumes that the 98.5% of the genome (because they supposedly genes) are transcribed in RNA. This happens, for the most part, but not - the genome is transcriptionally mostly dead Even more important, so far no one has claimed that once produced RNA did not function [1].

now to the junk DNA. Whenever in recent years, someone has an effect that is not the schema gene - mRNA - protein follows, he has the same evil unpacked junk DNA. Accordingly, so are all other molecular biologists so limited that everything in the genome, which is not that simple Scheme corresponds to dismiss as genetic garbage lying around the completely unnecessary and complicates the search for genes. But now comes the underdog, who confronts his great new discovery to the narrow-minded scientific establishment. Sure, that is so taken up a representation by the media like.
With this view, there is only one problem: it is wrong, and almost as long as we even know that there are genes and the DNA is the genetic material in the cell. Only a few years after the description of DNA structure by Watson and Crick in 1953, was the translation informed, in essence, that the production of proteins from the information of the mRNA. This was already clear that for RNAs this process are needed, none of which proteins are produced: the tRNAs and rRNAs. Also, the fact everyone learns in school. The basic assumption, non-coding RNAs with a function in the cell would be known only for a few years ago, is not only wrong - these RNAs are part of the establishment!

That is one aspect. The other side has the definition of the concept of junk DNA to do. First of all is not "waste" of which we do not know the function. With junk DNA elements in the genome are known, which have proven does not function! The Nobel laureate Sydney Brenner are in this video on iBioSeminars (from about 11:20) a very good Example. The Alu sequence is with a length of about 300 base pairs in the human genome into millions of copies before they do with it, depending on the estimate of 10-30% of the entire human genome! Function? No way! In the end, Alu elements parasites of genetic parasites.
So-called transposons are genetic elements that are specific sequences at their ends and encode between genes whose protein products recognize these endings and set there cuts in the DNA. A transposon can thus cut and paste your site in the genome of a hike to another. A benefit to the host genome, the first no, transposons use it only as a delivery vehicle. Alu elements and other similar sequences go this one step further: In order to carry genes themselves are too small. On their end but they also have the sequences that are recognized by the Transposonproteinen. Alu elements are therefore ex-transposons, which have saved the effort with the genes and use their still functioning Transposonkollegen. Again, however, no direct benefit to the host cell.
Larry Moran has in recent months, various elements in the human genome listed who have secured not function, that fall within junk DNA. The Alu elements are (listed under SINEs) also there. Overall, he is now, without details of all types of non-functioning elements in the genome to have more than 50% of the size of the genome - and that is a very conservative estimate!
points in the above video Sydney Brenner also points to a widespread misunderstanding of what the term concerned junk DNA. With junk is not meant in English namely the garbage that you throw it away. a better translation would be the word junk , according to Brenner things you can do just not that why do you store in the attic.

Most of the genome appears to be Unnecessary, it is - if you like - call it rubbish. Now as you well know, there are two kinds of rubbish: The rubbish you keep, Which we call junk, and the rubbish we throw away, Which we call garbage.

This understanding of junk DNA triggers on a frequent criticism directed against it in pleasure, just because we see no benefit for these elements is present, that does not mean that these sequences may be used at some point it!


[1] of the current debate on stochastic transcription and benefits of the resultant RNA apart.